Bacteria-Stimulated Metamorphosis: an Ocean of Insights from Investigating a Transient Host-Microbe Interaction

• Published in: mSystems Vol. 6; no. 4; p. e0075421
• Main Author: Shikuma, Nicholas J
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 31-08-2021
• Subjects: Bacteriology; Commentary; Sponsored by Floré: Early-Career Special Series; marine microbiology; natural products; symbiosis; MACs; contractile injection systems; larvae; metamorphosis; host-microbe interaction
• ISSN: 2379-5077; 2379-5077
• DOI: 10.1128/mSystems.00754-21

Recent research on host-microbe interactions has focused on intimate symbioses. Yet transient interactions, such as the stimulation of animal metamorphosis by bacteria, can have significant impacts on each partner. During these short-lived interactions, swimming animal larvae identify a desirable location on the seafloor and undergo metamorphosis into a juvenile based on the presence of specific bottom-dwelling bacteria. While this phenomenon is critical for seeding new animals to establish or maintain benthic ecosystems, there is an ocean of fundamental questions that remain unanswered. Here, I propose an updated model of how bacteria stimulate animal metamorphosis based on evidence that bacteria inject a stimulatory protein that prompts tubeworm metamorphosis. I consider what we hope to learn about stimulatory bacterial products, how animals recognize these products, and the consequences for both partners. Finally, I provide examples of how studying an enigmatic host-microbe interaction can serve as an engine for scientific discovery.